Choosing a power supply, switch fuse size

[Yanu]

Hi all, I'm new here.
I have qualified back in 1990 and worked only a few years in the trade. Now I'm back and I find myself a bit "rusty" and in need of a bit of help...

I have to wire a complex of coldstores and I have to make a fuse boards for a part of them. I have 6no 10 amp MCBs, 2no 20 amp MCBs and 8no 20 amp RCBOs in it. Just a few lights and sockets circuits. I have no idea what's going to be plugged in and for how long, the client can supply single or three phase.
What size switch fuse do you think I should use?
Thanks in advance

 

[Spoon]

Sorry Spoon.. how would you wire a socket circuit? wouldnt you use a 2.5 cable for it. Wouldnt you put a 20 amp rcbo for that?

My employer says that the sockets are for general use and to go with the maximum rating to cover ourselves

Why not 30A or 32A?
I would use the correct size cable for the installation method.

 

[Spoon]

I remember an engeneer once told me to put a max of 4 sockets on a circuit and I'm following that advice. What's the max you'd put?

As already mentioned above mate. The engineer was talking rubbish.
I would ask that the customer what quantity they wanted.

 

[Risteard]

Yes, they will be shipped to Scotland

Are these being wired to ET101 or BS7671 then?

 

[Yanu]

You said previously these cold stores are normally straight forward, what is different now. If you have no knowledge of the site then that should be your first port of call, either visit the site or see specifications for the site.

The coldstores usually comes with a fridge that has all the breakers pre installed, I only wire to them. This particular complex has a few rooms that are just "ambient", no fridge required. I have to wire lights and sockets in them and put a fuse board to feed them

 

[Spoon]

I have no knowledge of the site either. I have to do a job and looking for help, this seemed the right place for it. I seem to be getting lots of hassle here on how little I know and nobody is really telling me what they would do in my position

I am giving you advice mate....

 

[Yanu]

As already mentioned above mate. The engineer was talking rubbish.
I would ask that the customer what quantity they wanted.

I cant ask the customer how many sockets he wants in a circuit though... How many sockets do you put in a circuit when wiring a house?

 

[Yanu]

Hand dryers will require rcd protection for a start, there is not a limit of 4 sockets either, but if you don't think your capable of doing the job (that's not a jab at you by the way) id say to your boss that you don't think your able to, you probably shouldn't undertake it if you can't provide the correct protection for each circuit. Will you be able to test it when finished?

Thanks for the hand driers tip, you are right. It makes sense.
Yes, I can test them. I have a megger and perform a full test when the coldstores are finished

 

[Spoon]

I cant ask the customer how many sockets he wants in a circuit though... How many sockets do you put in a circuit when wiring a house?

I'm industrial. Don't do domestic.
If I did it would all depend on the size of the rooms and room function as to how many sockets I would put in.

 

[Yanu]

I am giving you advice mate....

Thanks Spoon I just thought it would be a simple enough task to wire a few lights and sockets and everybody is making a big deal about it without really telling me anything...

 

[Yanu]

Are these being wired to ET101 or BS7671 then?

I guess ET101. Are there many differences in your opinion? for a few lights and sockets?

 

[Risteard]

...

 

[Risteard]

I guess ET101. Are there many differences in your opinion? for a few lights and sockets?

Quite a few differences. This would fall within the scope of Controlled Electrical Works (requiring certification) - which would mean getting a RECI Inspector to certify it since you're not a RECI member. Not sure though whether this applies if they're being shipped to Scotland.

 

[Spoon]

Thanks Spoon I just thought it would be a simple enough task to wire a few lights and sockets and everybody is making a big deal about it without really telling me anything...

This may have me coming across as an arse (nothing new there), but I'm finding it hard to totally understand everything.

Correct me if I'm wrong with the below.
You have 6 rooms, used for coldstores, which you are going to add sockets and lights to.
You intend to have one dist board for supplying all the 6 rooms.
This contract is manufactured in Ireland and then shipped to Scotland.
Are these 'rooms' like shipping containers or something? What size are these rooms?

 

[elsparko]

I cant ask the customer how many sockets he wants in a circuit though... How many sockets do you put in a circuit when wiring a house?

shirley just check the architects drawings?

 

[Yanu]

This may have me coming across as an arse (nothing new there), but I'm finding it hard to totally understand everything.

Correct me if I'm wrong with the below.
You have 6 rooms, used for coldstores, which you are going to add sockets and lights to.
You intend to have one dist board for supplying all the 6 rooms.
This contract is manufactured in Ireland and then shipped to Scotland.
Are these 'rooms' like shipping containers or something? What size are these rooms?

Thanks spoon.
This complex has 11 "rooms" built and ship individually. They'll be assembled here in Ireland and shipped and put together in Scotland. 6 of them are coldstores and have fridges in them. 5 of them are only "ambient" and don't require a fridge. This rooms are about 13m x 3m average size.
Yes, I'm planning to have one distribution board for those 6 rooms.
With this distribution board I'm supplying:
25 lights, 5 foot LEDs,
23 sockets
2 hand driers
2 air conditioners

How would you build the distribution board with your knowledge and under the rule of your country?
I'd like one breaker for lights and one for sockets for every room

Thanks for your time